As an important reminder, we plan to shut down API Version 1 in the first week of November. If you haven't upgraded yet, please visit our upgrade guide. The Incompatibilities section contains a helpful list of known incompatibilities between Version 1 and Version 2 of the API. We did not preserve many of the undocumented functions between Version 1 and 2 of the API. Please join the Maps API discussion group if you have any problems.

The quickest way to upgrade is to update your Maps API <script> URL to refer to "v=2" instead of "v=1." Since Version 2 preserves the old GMap interface, your site should theoretically continue to work without any further changes. However, in practice, you may have to spend some time debugging. Once we shut down Version 1 of the API, we will serve Version 2 to your site, even if you are still specifying "v=1" in your <script> tag. For this reason, it is important that you test your site with "v=2" before November's transition.

Many of you have asked why we don't continue to leave Version 1 of the API available. Due to technical reasons, we will be able to deliver improved map tiles to API users by shutting down Version 1 of the API and transitioning sites to the new version. Version 2 contains many important enhancements to fundamental parts of the Maps API. We feel that these benefits will outweigh the transition costs in the long term.